Charge forming device



Oct. 18, 1932. F. E. ASELTINE CHARGE FORMING DEVICE Filed May 31 June nfor,

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Patented Oct. 18,

pa r-so srArss FRED E. ASELTINEUOF DAYTOLLOHICO, ASSIGNOR T DELCOrnonucrs oonronn'rioiv, or

PATENT. OFFICE.

DAYTON, OHIO, A CORPORATION OF DELAXVARE v CHARGE romaine DEVICEApplication filed May 31, '1930. Serial No. 457,694.

This invention relates to charge forming devices for internal combustionengines, and more particularly to devices of this character whichcomprise a plurality of primary carburetors, each of which deliversa'primary mixture of fuel and air to one of a plurality of secondarymixing chambers located adja- I cent the engine intake ports and inwhich the primary mixture is mixed; with additonalair under certainoperating conditions.-

Devices of this character are disclosed in the copending applications ofFred E. Aseltine and VVilfordH. Teeter, Serial No. 221,- 871, filedSeptember 22, 1927, and WVilford H.

. Teeter, Serial No. 221,372, filed September It is an object of thepresent invention to provide novel means for operating the throttles andto secure better regulation of the mixture proportions- According tovthis invention, instead of operating the secondary throttle by a lostmotion connection from theprimary throttle, the secondary throttle isoperated directlyiby the operator through manually operating means andthe primary throttle is connected to a" suction operated valve in thesecondary air passage, whereby" said primary throttleis operated onlythrough the medium of said automatic suction operated valve, and itsmovement isdependent on the suctioneffec ti-ve on said valve and theflow of air throu-gh the secondary air passage. 1 .1

Further objects and advantages of the present invention will be apparentfrom the fol Y lowing description, reference being bad to theaccompanying drawing wherein a preferred embodiment of one form of thepresentinvention is clearly shown. I

In the drawing: p I

Fig. 1 is a'vertical, longitudinalsection through achargeforming deviceconsidered in accordance with the present invention.

Fig. 2 is a fragmentary elevation of such device showing the operatingconnections for the throttle valve.

Fig. 3 is a section on the line of The device disclosed comprises a mainair manifold 10, having three outlet branches,

the middle branch 12 being shown herein.

Each outlet branch communicates with oneof theports of a multicylinderengine and is l provided with an attachingfiange 14 for securing themanifold to the engine blockin the usual manner, while a flange 16 isprovided at the inlet for securing a carburetor The carburetor unitcomprises 1 of the housing to admit air thereto. A casting 28,supporting devices disclosed later,

is secured to the'bottom of the main housing 20 and a sheet metal fuelbowl is held tight I against an annular shoulder 32 formed on saidcasting 28. Fuel is supplied to the fuel I bowl from a main source ofsupply and its flow is controlled by afloat 34, operating in the usualmanner to maintain a substantially constant level of fuel in the bowl. J7

Fuel flows from the bowl to a plurality of fuel nozzles 36, one of whichis located in each .of the primary mixing chambers 38,

more fully described later. The nozzles are supplied with fuel through adelivery con duit, comprising a vertical passage 40 having a fixed fuelinlet 42 and a high speed fuel inlet 44 controlled by a valve 46 oper-'ated asdescribed in. the first of the above mentioned applications. Thepassage 40 connects at its upper end with a horizontal fuel canal 48,which suppli'es fuel directly to each of the fuel nozzles 36 throughorifices 50. A two-stage, fuel metering valve 52 regulates the flow offuel through the fuel delivery conduits and a check valve 54 received ina chamber 56, prevents the return of fuel on reduction of suction in themixing chambers,

all of the above described structure being identical with that morefully disclosed in application Serial No.' 221 ,371.

Eachprimary fuel nozzle'is provided with a main fuel outlet 58in the topthereof and a secondary-fuel outlet comprising twoori-' fices 60 and 62in the wall of the nozzle near the bottom of themixing chamber. The:secondary fuel outlets-function at all times, while the suction in theprimary mixing chamber is sufficient to lift fuel from the main outletonly at relatively high speeds. The primary mixing chambers comprise theenlarged anterior ends of primary mixture passages 64, which areparallel to each other and close together, as indicated in Fig. 3. Whenthe carburetor is attached to the engine, these passages registerwithconduits which convey the primary mixture to secondary mixing chambers,as fully disclosed in the above application. One of theseconduitscomprises the tube 66 fined in the wall of branch 12 of the manifoldwhich supplies primary mixture to the secondary mixing chamber in thatparticular manifold branch.

A single throttle valve 88 which' extends across all of the primarymixture passages, is provided with grooves 70,.Which register with saidpassages and control the flow therethrough.- This throttle is journalledfor ro tation in the main housing and is operated by the means and inthe manner hereinafter more fully described.

Air is admitted 'to-the carburetor through the coupling 26 and iscontrolled by an air valve 72 hold tight against a. seat 7% by a spring7 6, received between the valve and a flange 78, secured to a sleeve 80,slidable'on a sleeve 82, fixed in the housing and guiding the movementsof the. stem. 84L to which the air valve is secured. The air valve isadapted to be held closed to aid .in starting the engine by lifting theflange 78'1nto engagement with the air valve through the medium of.means. which is not clisclosedherein but is described. in applicationSerial'No. 221,371.

Air to carry the starting fuel. to the engine cylinderswhen the airvalve is closed is supplied, by the orifices 86.

The valve 72 admits air to a main air chamber 88, from which the airflows to the primary mixingchambers through an" orifice 90 in the bottomof the chamber 88 and to secondary mixing chambers in. the manifoldthrough a secondary air passage 92, which communicates wlth the manifoldinlet. The flow of air through the passage 92 is controlled by amanually operable main throttle valve 94, and a suction operated Valve96, secured to shafts 98 and 100 respectively, which are journalledforrotation in the main housing, the shaft 100 being 05 center/with respectto the valve 96'.

Accordingto the present invention, the primary throttle valve68 isnot'operated direct ly by a connection extending to the operator inpthemanner disclosed in the earlier applications above referred to. On thecontrary, the'main throttle valve 94.1 in the secondary air passageis-operatedin this manner'andto this end an operating arm 1.02 is.secured. in any desirable mannento' the end of .the shaft 98 and sucharm'i'is pivotally connected .to 'arod10 1,'whichiis providedwith an oifset endz106, extendingithrou 'h thee nd. 2( In of. the arm 102, asindicated :in

order to operate the primary throttle, the latter is provided with aspindle 108 projecting therefrom, to which is secured in any desirablemanner, an operating arm 110, pivotally connected to the oil-set end 112of an operating link 114,- the opposite end of which, 116., is bent andprojects through an orifice in an arm 118, secured in any desirablemanner to the end of the shaft 100, on

which the suction operated valve 96 is secured." This valve is providedat its upper edge with an arcuate lip 120, which may be a separate piecesecured to the valve or formed integral therewith, and projects from thevalve, while the lower half of the Valve is thickened so as toconstitute a weight'122, which tends to close the valve from any openposition. It will be clear that whenever the valve 94 is opened,the'action of the air against the valve 96, the shaft o'fiwhich is offcenter, also opens said valve'96. The projecting. lip 1s provided-topreventany marked decrease in the force tending to open the valve as 1the latter moves toward open position. Due

to the lip 120 the effective area of the upper partjof the valve 96 aspresented to the ingoing air flowing throughthe secondary air passage,decreases very little as thevalve is opened. Also during the openingof-the valve the closing effect of the weight 122 is slightly decreaseddue to the fact that part of the weight moves to a' position to theright ofthe shaft 100 and. becomes etlective to aid.

in opening'the valves. By properly design ing the lip and weight theeftective force required. to open the valve may be made sub stantiallyconstant throughout the entire opening movement of the valve. Or ifdesired the lip and weight may be so proportioned; that the forcerequired to open the valve will. increase 'as the velocity of the airflow throughthe secondary air passage increases, or any otherdesiredresult may be obtained. i

As the suction operated valve 96 is moved.

pot is provided comprising a cylinder 12% which. as shown is slidable insleeve 126 in.- tegral with the casting 28, and a piston 128 secured. tothe lower end of'the valve stem 84 and slidable within the cylinder 124.This particular dash-pot is providedfor thev purpose of enriching themixture for acceleration, the cylinder being lifted as the throttle isopened, specific details of construction of.

the dash-pot constitute nopart of the present invention whatever and itis not necessary to employ the particular dash-pot shown, but

as illustrated the cylinder may be lifted by an arm 130 as described inthe earlier applications, but the dash-pot may be of any conventionalconstruction.

It will be obvious that by the provision of the throttle operatingmechanism disclosed herein the primary throttle is operated entirelyautomatically in accordance with the flow of air through the secondaryair passage, and the position of the primary throttle may vary withchanges in thevelocity of flow through said secondary air passage, Whilethe secondary air throttle valve remains in fixed position. 7

It should also be clearthat by properly proportioning thelip'120 andweight 122 the mixture proportions may be regulated and certaindifficulties such as enrichment of the mixture on opening of thethrottle because of too much increase in the velocity head at the fuelnozzles, may be largely eliminated. Forinstance, if it be found, thatwhen the primary throttle and secondary air throttle are moved throughthe same degree, the mixture becomes too rich. The device may be soconstructed, that the primary throttle will not be opened as rapidl asvalve 94:, thus reducing the velocity hea at the nozzles, withcorresponding reduction in suction and flow of fuel from such nozzles.

. While the form of embodiment of the present invention as hereindisclosed, constitutes a preferred form, it is to be understood thatother forms might be adopted, all coming within the scope of the claimswhich follow.

What is claimed is as follows:

1. A charge forming device for internal combustion engines comprising aprimary mixture passage, means for supplying fuel and air thereto, asecondary mixing chamber .into which said mixture passage delivers aprimary mixture of fuel and air, a secondary air passage supplying airthereto, and means controlled by the flow of air through the secondaryair passage for increasing the quan tity of primary mixture flowingthrough the primary mixture passage as the flow of secondary airincreases.

2. A charge forming device for internal combustion engines comprising aprimary mixture passage, means for supplying fuel and air thereto, asecondary mixing chamber into which said mixture passage delivers aprimary mixture of fuel and air, a secondary air passage supplying airthereto, an 7 air throttle therein, av primary throttle in said primarymixture passage and means controlled by the flow of air through said secondary air passage for controlling the position of'the primary throttlein accordance with the position of the air throttle.

3. A charge forming device for internal combustion engines comprising aprimary mixture passage, means for supplying fuel and air thereto, asecondary mixing chamber into which said mixture passage delivers aprimary mixture of fuel and air, a secondary combustion enginescomprising a primary mixture passage; means for-supplying fuel and airthereto, a secondary mixing chamber into which said lmixture passagedelivers, a primary throttle for controlling the flow through theprimary mixture passage and a pressure responsive device for operatingsaid throttle, said device being constructed to openthe throttle as theengine speed increases.

. 5. A charge forming device for internalcombustion engines comprising aprimary mixture passage, means for supplying fuel and air thereto, asecondary mixing chamber into which said mixture passage delivers, anautomatically operated primary throttle for controlling the flow throughthe primary IHiT ICHiG'PdSSflQG and'constructed to open as the enginespeed increases and manually .op-

erated means for controlling the operation of said throttle.

6. A charge forming device for internal combustion engines comprising aprimary mixturepassage, means for supplying fuel and air' thereto, asecondary mixing chamber into which saidmixture passage delivers, a

into which said mixture passage delivers, a pr mary throttl e forcontrolling the flow through'the primary mixture passage, a sec ondaryair passage supplying air to said secondary mixing chamber, meansoperated by the flow of air through saidsecondary air passageforoperating said primary throttle in ,accordance with its own movementand i'nanually operated means for controlling the operation of saidlastmentioncd means.

'8. A charge forming device for internal coinbusti on "enginescomprising a primary mixture passage, means for supplying fuel and airthereto, a' secondary mixing chamber into-Which sald mixture passagedelivers, a

primary -throttle for; controlling the flow and air thereto, a secondarymixing chamber into which the primary mixture passage delivers a primarymixture of fuel and air, a primary throttle controlling the flow throughthe primary mixture passage, a secondary air passage supplying air tothe secondary mixing chamber, an air throttle for controlling the flowof air through the secondary air passage, and means for operating theprimary throttle the effectiveness of which is controlled by the airthrottle.

10. A charge forming device for internal combustion engmes comprising aprimary.

mixture passage, means for supplying fuel and air thereto, a secondarymixing chamber into which the primary mixture passage delivers a primarymixture of fuel and air, a

7. primary throttle controlling the flow through the primary mixturepassage, a secondary air passage supplying air to the secondary mixingchamber, an air throttle for controlling the flow of air through thesecondary air passage, and means for operating the pri mary throttle,said operating means being ineffective when the air throttle is closedand adapted to be rendered effective when the air throttle is opened.

11. A charge forming device for internal combustion engines comprising aprimary mixture passage, means forsupplying fuel and air thereto, asecondary mixing chamber into which the primary mixture passage deliversa primary mixture of fuel and air, a primary throttle controlling theflow through the primary mixture passage, a secondary air passagesupplying air to the secondary mixing chamber, and a suction operatedvalve in said secondary air passage, for controlling the flowtherethrough and operating the primary throttle in accordance with itsown movement.

12. A charge forming device for internal combustion engines comprising aprimary mixture passage, means for supplying fuel and air thereto, asecondary mixing chamber into which the primary mixture passage deliversa primary mixture of fuel and air, a primary throttle controlling theflow through the primary mixture passage, a secondary air passagesupplying air to the secondary mixing chamber, a suction operated valvein said secondary air passage for controlling: the flow therethrough,operating, connections mixture passage, "means 'for supplying fuel andair thereto, a secondary mixing chamher into which the primary mixturepassage delivers a primary mixture of fuel and air, a primary throttlecontrolling the flow through the primary mixture passage, a secondaryair passage supplying air to the secondary inixingchamber, a manuallyoper able valve in the secondary air passage, a suction operated valvein said secondary air passage adapted to open on opening movements ofthe manually operable valve, and means for determining the amount ofmovemen'fi of said suction operated valve for any given movement of themanually operable valve. I

14." A charge forming device for internal combustion engines comprisinga, primary mixture passage, means for supplying fuel and air thereto, asecondary mixing chamber into which the primary mixture passage deliversa primary mixtureof fuel and air, a primary throttle controlling theflow through the primary mixture passage, a secondary air passagesupplying air to the secondary mixing chamber, a-manually operable valvein the secondary air passage a suction operated V valve in saidsecondary air passage adapted to openon opening movements of themanually operable'valve, means for'determining'; the amount of movementof said suction operated valve for any given movement of the manuallyoperable valve, and a primary throttle operated bysaid suction operatedvalve.

' In testimony whereof I hereto aiflx my signature.

FRED E. ASELTINE.

